The present invention relates to a suction transfer assembly of a vial having a chamber filled with a medicament liquid, such as a hazardous liquid, and closed by a stopper on which the vial is longitudinally slidable, and a flow path containing adapter connectable to the vial by a hollow needle that penetrates the stopper, usable with a suction operating dispenser device, e.g. a syringe, lockably connectable to the adapter at a check valve in the flow path to transfer liquid from the vial to the device, with simultaneous compensating vial movement relative to the stopper under external atmospheric pressure to reduce the chamber volume by an amount equal to the liquid transferred, yet preventing leakage from the adapter on disconnecting the device.
Devices that hold and dispense hazardous materials, such as hazardous liquids in the medical field, are dangerous to use due to possible leakage from the device and contamination of the environment or user. Among such hazardous materials are cytotoxic or antineoplastic (oncology) drugs administered in chemotherapeutic treatment of cancer. They are usually stored as an injectable solution in a stoppered vial, prone to aerosol or droplet formation, as when manipulated at differential pressures in withdrawing a dosage into a syringe, since these operations change the saturated vapor pressure conditions of the volatilized constituents in the air space above the solution in the vial.
U.S. Pat. Nos. 4,768,568 and 4,834,149 to Fournier et al show a hazardous material vial apparatus and conjoint operating method, in which the neck of a vial closed by a stationary stopper and containing a small amount of hazardous material powder and captive air is enclosed by a coaxial snap-on pressure release housing, formed as an open ended hollow cylinder whose outer end is closed by a septum and whose inner end openly faces the stopper, and which has an air pressure releasing hydrophobic filter vent near its outer end and a shiftable piston that divides the cylinder into an outer atmospheric chamber containing the vent and an inner pressure chamber openly facing the stopper.
According to these two patents, the needle of a syringe penetrates the septum, piston and stopper to add a small amount of liquid to the powder to form a hazardous solution and a saturated vapor thereof at increased pressure in the air space above the solution due to the added liquid volume. On inverting the arrangement, the increased pressure refills the syringe with the solution and returns the vial to atmospheric pressure. As the needle is removed, any escaping solution and aerosol formed from the vapor under the differential pressure conditions are retained in the inner chamber while the piston move outwardly to adjust this chamber to atmospheric pressure, or are retained by the hydrophobic vent if they reach the outer chamber.
Alternatively, according to these patents, if the solution is not used immediately, the arrangement is kept upright, enough air is drawn into the syringe to return the vial to atmospheric pressure, and the needle removed as before, but with the air in the syringe being discharged into the outer chamber for safe exit into the atmosphere while any hazardous solution and aerosol are retained by the hydrophobic vent. When the solution is to be used, the syringe is loaded with a volume of air equal to that of the solution to be removed, this air is charged to the vial to increase its air pressure, the arrangement inverted, the solution volume drawn into the syringe and the vial returned to atmospheric pressure, and the needle removed as before.
It would be desirable to provide a suction transfer assembly for a medicament liquid, especially a hazardous liquid, that permits safe and easy transfer of the liquid from its container to a suction operating dispenser device such as a syringe, yet avoids leakage on detaching the device from the assembly.